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Développement de membranes MOF nanocomposites à base de ZIF / Development of ZIF-based nanocomposite Metal-Organic Framework membranesSalvador Levehang, Claudia 16 December 2014 (has links)
Les réseaux zéolithiques à base d'imidazolate (e.g. ZIF-8) sont des matériaux membranaires attractifs pour la séparation de gaz, sous réserve de pouvoir disposer de membranes de haute qualité, stables et reproductibles sur des supports industriels. Dans ce travail plusieurs stratégies ont été examinées pour développer des membranes nanocomposites à base de ZIF-8 confiné dans les macropores de supports céramiques tubulaires. Trois approches ont été comparées: i) croissance de germes, ii) croissance in situ et iii) conversion de ZnO. L'influence des paramètres de synthèse (formulation des solutions de précurseurs, température & durée de réaction, type de support & prétraitement…) sur les caractéristiques et performances des membranes a été étudiée. Le protocole optimum retenu repose sur la conversion solvothermale de couches minces de ZnO déposées par ALD sur les grains du support. Les membranes nanocomposites ZIF-8/ZnO/α-Al2O3 sont sélectives pour la séparation de gaz contenant H2. / Zeolitic Imidazolate Frameworks (e.g. ZIF-8) are attractive membrane materials for gas separation, provided that high quality, stable and reproducible membranes can be prepared on industrial supports. In this work several strategies were investigated in order to develop nanocomposite ZIF-8 based membranes confined in the macropores of tubular ceramic supports. Three approaches were compared: i) seeded growth, ii) in situ growth and iii) ZnO conversion. The influence of synthesis parameters (precursor solution formulation, reaction temperature & duration, support type & pre-treatment…) on membrane characteristics and performance were studied. The selected optimum protocol was based on the solvothermal conversion, using a 2-methylimidazole/methanol solution, of a ZnO thin layer uniformly deposited by Atomic Layer Deposition on the grains of a ceramic support. The nanocomposite ZIF-8/ZnO/α-Al2O3 membranes exhibited enhanced selectivities for the separation of H2-containing gas mixtures.
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Synthetic Two-Dimensional Materials: A New Paradigm of Membranes for Ultimate SeparationZheng, Zhikun, Grünker, Ronny, Feng, Xinliang 07 May 2018 (has links) (PDF)
Microporous membranes act as selective barriers and play an important role in industrial gas separation and water purification. The permeability of such membranes is inversely proportional to their thickness. Synthetic two-dimensional materials (2DMs), with a thickness of one to a few atoms or monomer-units are ideal candidates for developing separation membranes. In this Progress Report, we present groundbreaking advances in the design, synthesis, processing, and application of 2DMs for gas and ion separations, as well as water desalination. After the introduction in Section 1, this report describes the syntheses, structures, and mechanical properties of 2DMs in Section 2. In Section 3, we will discuss the established methods for processing 2DMs into selective permeation membranes and address the separation mechanism and their performances. Finally, current challenges and emerging research directions, which need to be addressed for developing next generation separation membranes, are summarized in the Conclusion and Perspective.
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IMPLEMENTATION OF OXYFUEL COMBUSTION IN A WASTE INCINERATION CHP PLANT : A Techno-Economic AssessmentSaleh, Mostafa, Hedén Sandberg, Anton January 2021 (has links)
Global energy demand is predicted to rise in the coming decades, necessitating a shift to renewable energy sources to mitigate greenhouse gas emissions. However, due to the inability to supply renewable energy around the clock, it is estimated that only by adding an important technology, carbon capture and storage (CCS), it could be possible to reduce 80% of the 1990s greenhouse gas emissions. CCS aims to reduce anthropogenic carbon emissions by capturing CO2 from flue gases, transporting, and permanently storing or reutilizing industrially. The CCS approach includes three technologies: post-combustion capture, pre-combustion capture, and oxyfuel combustion, with the latter being the emphasis of this thesis. Based on the case study of Mälarenergi’s Refused-derived waste-fired CHP plant, this thesis investigates the viability of converting existing non-fossil fueled CHP plants to oxyfuel combustion. A thorough technical investigation based on analyzing the impact of oxyfuel combustion on system performance was conducted through system modeling using a process simulator, Aspen plus. The model in this thesis considers the development of an air separation unit (ASU), a CHP plant, and a cryogenic CO2 purification unit (CPU). All of which are validated through calibration and comparison with real-world data and similar work. To investigate the influence of employing oxyfuel combustion on the generation of both heat and electricity, two different scenarios were comprised, including recirculating flue gas before and after flue gas condensation. In addition, an analysis of the oxygen purity was conducted to assess the most optimal parameters with the least impact on system performance. Moreover, a detailed eco- nomic assessment comprising the costs of integrating oxyfuel combustion was also conducted. The findings of this thesis show that integrating waste incineration CHP plants with oxyfuel combustion for CO2 capture entails promising features under the condition of 97% oxygen purity and a flue gas recirculation system taking place after flue gas condensation. This is owing to (i) modest imposed energy penalty of approximately 8.7%, (ii) high CO2 recovery ratio, around 92.4%, (iii) total investment cost of approximately 554 M$ during a 20-year lifetime, and (iv) cost of captured CO2 of around 76 $/ton. Aside from system modeling, this thesis pre- sents an overview of the current state-of-the-art technology on the different separation and capture mechanisms. It is important to highlight that the goal of this thesis is not to provide a comprehensive review but rather to present an overall picture of the maturity of the different mechanisms. The findings point to the cryogenic separation mechanism as the most mature technology for both oxygen production and capturing of CO2 during oxyfuel combustion.
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Design Process for the Containment and Manipulation of Liquids in MicrogravityMeek, Chris 01 January 2019 (has links)
In order to enhance accessibility to microgravity research, the design process for experiments on the ISS must be streamlined and accessible to all scientific disciplines, not just aerospace engineers. Thus, a general design and analysis toolbox with accompanying best practices manual for microgravity liquid containment is proposed. The work presented in this thesis improves the design process by introducing a modular liquid tank design which can be filled, drained, or act as a passive liquid-gas separation device. It can also be pressurized, and used for aerosol spray. This tank can be modified to meet the design requirements of various experimental setups and liquids. Furthermore, rough simulations of this tank are presented and available to the user for modification. The simulation and design methodology for other general cases is discussed as well. After reading this thesis, the user should have a basic understanding of how liquids behave in microgravity. She will be able to run simple simulations, design, build, test, and fly a liquid management device which has been modified to suit the requirements of her specific experiment.
The general tank design can be manufactured using 3-D printing, traditional CNC milling, or a combination thereof. The design methodology and best practices presented here have been used to design tanks used in experiments on the International Space Station for Budweiser and Lambda Vision. Both tanks functioned nominally on orbit. While the specific data from these experiments cannot be presented due to proprietary restrictions, using this thesis as a design guide for new experiments should yield favorable results when applied to new tank designs. If the reader has any questions or would like an updated design process, the author’s preferred contact information can be found using the Orcid iD: 0000-0002-2617-2957 .
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Novel Applications of Co-Extruded Multilayer Polymeric FilmsArmstrong, Shannon Renee 23 August 2013 (has links)
No description available.
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Infrared Spectroscopy of Trapped Gases in Metal-Organic FrameworksSchloss, Jennifer M. 21 June 2011 (has links)
No description available.
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Synthesis and Characterization of Hydrophilic-Hydrophobic Poly (Arylene Ether Sulfone) Random and Segmented Copolymers for Membrane ApplicationsNebipasagil, Ali 26 January 2015 (has links)
Poly(arylene ether sulfone)s are high-performance engineering thermoplastics that have been investigated extensively over the past several decades due to their outstanding mechanical properties, high glass transition temperatures (Tg), solvent resistance and exceptional thermal, oxidative and hydrolytic stability. Their thermal and mechanical properties are highly suited to a variety of applications including membrane applications such as reverse osmosis, ultrafiltration, and gas separation. This dissertation covers structure-property-performance relationships of poly(arylene ether sulfone) and poly(ethylene oxide)-containing random and segmented copolymers for reverse osmosis and gas separation membranes.
The second chapter of this dissertation describes synthesis of disulfonated poly(arylene ether sulfone) random copolymers with oligomeric molecular weights that contain hydrophilic and hydrophobic segments for thin film composite (TFC) reverse osmosis membranes. These copolymers were synthesized and chemically modified to obtain novel crosslinkable poly(arylene ether sulfone) oligomers with acrylamide groups on both ends. The acrylamide-terminated oligomers were crosslinked with UV radiation in the presence of a multifunctional acrylate and a UV initiator. Transparent, dense films were obtained with high gel fractions. Mechanically robust TFC membranes were prepared from either aqueous or water-methanol solutions cast onto a commercial UDEL® foam support. This was the first example that utilized a water or alcohol solvent system and UV radiation to obtain reverse osmosis TFC membranes. The membranes were characterized with regard to composition, surface properties, and water uptake. Water and salt transport properties were elucidated at the department of chemical engineering at the University of Texas at Austin.
The gas separation membranes presented in chapter three were poly(arylene ether sulfone) and poly(ethylene oxide) (PEO)-containing polyurethanes. Poly(arylene ether sulfone) copolymers with controlled molecular weights were synthesized and chemically modified to obtain poly(arylene ether sulfone) polyols with aliphatic hydroxyethyl terminal functionality. The hydroxyethyl-terminated oligomers and α-ω-hydroxy-terminated PEO were chain extended with a diisocyanate to obtain polyurethanes. Compositions with high poly(arylene ether sulfone) content relative to the hydrophilic PEO blocks were of interest due to their mechanical integrity. The membranes were characterized to analyze their compositions, thermal and mechanical properties, water uptake, and molecular weights. These membranes were also evaluated by collaborators at the University of Texas at Austin to explore single gas transport properties. The results showed that both polymer and transport properties closely related to PEO-content. The CO2/CH4 gas selectivities of our membranes were improved from 25 to 34 and the CO2/N2 gas selectivity nearly doubled from 25 to 46 by increasing PEO-content from 0 to 30 wt.% in polyurethanes.
Chapter four also focuses on polymers for gas separation membranes. Disulfonated poly(arylene ether sulfone) and poly(ethylene oxide)-containing polyurethanes were synthesized for potential applications as gas separation membranes. Disulfonated polyols containing 20 and 40 mole percent of disulfonated repeat units with controlled molecular weights were synthesized. Poly(arylene ether sulfone) polyols and α,ω-hydroxy-terminated poly(ethylene oxide) were subsequently chain extended with a diisocyanate to obtain polyurethanes. Thermal and mechanical characterization revealed that the polyurethanes had a phase-mixed complex morphology. / Ph. D.
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Liquides ioniques pour la séparation des d'hydrocarbures gazeux / Ionic liquids for the separation of gaseous hydrocarbonsMoura, Leila 16 June 2014 (has links)
L'objectif de ces travaux était de synthétiser, caractériser et étudier le potentiel d'une sélection de liquides ioniques, pour la séparation de l'éthane et de l'éthène. L'influence dans l'absorption de l'éthène de la présence de trois cations métalliques, le lithium (I), le nickel (II) et le cuivre (II) dans un liquide ionique était également étudiée. Les liquides ioniques sélectionnés sont basés sur le cation imidazolium contenant des groupes fonctionnels au niveau de la chaine alkyle latérale. Les anions choisis sont le bis(trifluorométhylsulfonyl)imide, [NTf2], la dicyanamide, [DCA] et le méthylphosphite, [C1HPO3]. Sachant qu'un solvant de séparation idéale doit avoir une capacité d'absorption et une sélectivité de séparation élevées, une faible viscosité, une haute stabilité thermique et une cinétique d'absorption rapide pour le gaz sélectionné. Pour évaluer ces propriétés pour les milieux sélectionnés, plusieurs paramètres ont été déterminés la densité et la viscosité des liquides ioniques ainsi que l'absorption de chaque gaz dans les liquides ioniques. L'absorption de l'éthane et de l'éthène dans les liquides ioniques purs ainsi que dans les solutions de liquide ionique + sel métallique a été mesurée dans une gamme de températures comprises entre 303.15 K et 353.15 K et pour des pressions proches de l'atmosphérique. La sélectivité idéale des liquides ioniques pour l'absorption de l'éthane par rapport à l'éthène a ainsi pu être déterminée. La détermination de l'absorption en fonction de la température a permis d'accéder aux propriétés thermodynamiques de solvatation de ces gaz dans des liquides ioniques et à comprendre la manière dont les liquides ioniques interagissent avec ces solutés comment les liquides ioniques se structurent autour de ces molécules / The goal of this research was to synthesize, characterize and study the potential of selected ionic liquids as solvents for the separation of ethane and ethene. The influence on ethene absorption of the presence of three different metallic cations, lithium (I), nickel (II) and copper (II) in an ionic liquid was also studied. The selected ionic liquids are based in the imidazolium cation containing a functionalization in the alkyl side chain. The chosen anions were the bis(trifluorosulfonyl)imide, [NTf2], the dicyanamide, [DCA] and the methylphosphite, [C1HPO3]. Several parameters were taken into account for this primary evaluation, such as measurements of density, viscosity and absorption of each gas in the ionic liquids, since an ideal separation solvent should have a high absorption capacity and gas selectivity, low viscosity, high thermal stability and fast absorption kinetics for the selected gas. The absorption of the 2 gases in the pure ionic liquids and ionic liquid + metallic salt solutions was measured in the temperature range between 303.15 K and 353.15 K and for pressures close to atmospheric. The ideal selectivity of the ionic liquid for the absorption of ethane compared to ethene was determined. The determination of the gas solubility in function of the temperature allowed access to the thermodynamic properties of solvation of the gases in the ionic liquids, and a deeper understanding of the gas-ionic liquid interactions and the structure of the solution
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Estudo experimental, simulação numérica e modelagem fenomenológica da separação gravitacional de gás no fundo de poços direcionais / Experimental study, numerical simulation and phenomenological modeling of gravitational separation of gas in down-hole directional wellsMendes, Fernando Augusto Alves 30 August 2012 (has links)
Propõe-se o estudo do separador gravitacional de fundo de poço do tipo shroud invertido para poços direcionais e horizontais. A geometria inovadora é observada pela inclinação imposta, solução que transforma um escoamento vertical descendente, veloz e caótico, num escoamento inclinado e segregado em canal livre. Com a inclinação, minimizasse a incorporação de gás, no impacto do escoamento em superfície livre contra a interface de líquido formada pelo nível do anular interno (NAI), e a segregação é incrementada devido ao gradiente de velocidades e ao aparecimento da componente da gravidade na direção radial do poço de petróleo. O trabalho experimental tem como uma de suas metas o levantamento da eficiência de separação em função das vazões de líquido e gás, do ângulo de inclinação e o grau de interferência do escoamento no duto anular formado entre o separador e a parede do poço de petróleo, chamado neste trabalho de anular externo. Foi feito um trabalho de semelhança dimensional e foram detectados os números adimensionais pertinentes ao problema. Constatou-se que a vazão de gás e o escoamento no anular externo não interferem na eficiência de separação. Além disso, foi realizado um trabalho de caracterização dos padrões do escoamento gás-líquido em duto anular, através de visualização e análise no domínio do tempo e da frequência do sinal dinâmico da queda de pressão. Também são propostos dois modelos matemáticos, um modelo fenomenológico baseado em princípios físicos fundamentais, que foi capaz de prever com eficácia a região de máxima eficiência do separador shroud invertido, e um modelo numérico, que reproduziu a fenomenologia do processo de separação do gás. / This research project proposes the study of the inverted-shroud gravitational gas separator for directional and horizontal wells. The innovative geometry is observed by the inclination that transforms a vertical, fast and chaotic downward flow into an inclined and segregated free channel flow. Due to inclination, the incorporation of gas at the internal gasliquid interface (NAI) is minimized; the segregation is increased due to the velocity gradient and the gravitational term that arises in the radial direction of the oil well. One of the aims of the experimental work is the obtaining of new data of gas separation efficiency as a function of the flow of liquid and gas, inclination angle and the evaluation of the degree of interference of the external annular duct flow. A dimensional analysis was undertaken to identify the relevant dimensionless numbers. It was found that the gas flow and the flow pattern in the external annular duct do not interfere in the separation efficiency. A flow pattern characterization was carried out through visualization and time and frequency domain analysis of differential pressure signature signal. Two mathematical models are proposed, a phenomenological model based on fundamental physical principles, which was able to predict with good accuracy the region of maximum separation efficiency, and a numerical model, which reproduced the phenomenology of the gas separation process.
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Separação gravitacional de gás em um duto anular inclinado: estudo experimental e modelagem fenomenológica / Gravitational gas separation in an inclined annular channel: experimental study and phenomenological modelingVidal, Luis Enrique Ortiz 22 April 2010 (has links)
O presente trabalho apresenta um estudo associado à separação de gás para escoamento gás-líquido em um duto anular inclinado. Esse tipo de escoamento e geometria são encontrados em separadores de gás do tipo shroud invertido na indústria de petróleo quando utilizadas técnicas de bombeamento para a exploração de poços. A presença de gás livre a montante da bomba é uma das maiores limitações dos sistemas de bombeamento, por acarretar cavitação e falhas dinâmicas nos equipamentos. O presente estudo tem por objetivo garantir a separação total de gás livre a montante da bomba através da proposição de um separador do tipo shroud invertido em tubulação inclinada para aplicação na exploração de petróleo em poços direcionais. Um estudo experimental com ar e água como fluidos de trabalho a pressão quase atmosférica foi desenvolvido visando a compreensão da fenomenologia do separador shroud invertido. Foram observados escoamentos em duto anular do tipo: bifásico gás-líquido ascendente, monofásico em canal livre e bifásico gás-líquido descendente devido ao fenômeno de aeração; foram coletados também dados de eficiência de separação em função do ângulo de inclinação, vazão do líquido e queda de pressão entre o shroud e a saída do tubo de produção. Encontrou-se uma variável de extrema importância no fenômeno de separação até agora não reportada na literatura: o nível do anular interno do shroud (NAI). Um modelo fenomenológico que prevê a separação total do gás foi desenvolvido a partir da interpretação dos fenômenos físicos observados experimentalmente. Uma correlação inédita para a modelagem do fenômeno de dissipação de energia cinética turbulenta vinculado à separação do gás é proposta. O modelo foi validado qualitativamente com dados da literatura e ajustado com os dados coletados neste trabalho, mostrando boa concordância. / This paper presents a study associated with gas separation in an inclined gas-liquid annular-duct flow. This type of flow and geometry are found in shroud-inverted gas separators applied to petroleum industries when using pumping technique for oil production. High void fraction at the pump suction of is one of the most important limitations of the SCP technique, causing cavitation and dynamics failures in the equipment. The present study aims to provide a solution for the total gas separation through the use of an innovative inclined inverted-shroud separator for directional wells. An experimental study, where air and water at near atmospheric pressure constituted the working fluids, was carried out to understand the phenomenology of the inclined inverted-shroud separator. Different annular-duct flows were observed: upward gas-liquid flow, single-phase open channel flow, downward gas-liquid flow due to the phenomenon of aeration; also new data of separation efficiency were collected as a function of inclination angle, liquid flow rate and pressure drop between the shroud and production pipe outlet. One of the most significant findings is that the liquid level of the inner annular channel (NAI) of the shroud is a very important variable in the phenomenon of separation; so far this was not reported in the literature. Based on the observations, a phenomenological model that predicts total gas separation is proposed. A new correlation for the modeling of the dissipation of turbulent kinetic energy associated with the gas separation is presented. The model was qualitatively compared with available data from the literature and quantitatively adjusted against the new experimental data obtained in this work, and the agreement was quite good.
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